Effects of marinating process on mussels physicochemical and microbiological quality attributes during refrigerated storage

Abstract

In Tunisia, mussels Mytilus galloprovincialis are not familiar seafood because of cultural influence and convenience aspects. The aim of the present study is to develop a ready to eat seafood product as a novel variety of mussel. Marinating process using acid, salt and vegetable oil was chosen in order to achieve a longer shelf life, to improve taste and to maintain nutritional quality of the product. Synergistic effect of different pickling agents (acetic acid, salt and vegetable oil) was evaluated on physicochemical (pH and water activity), microbiological, chemical (TVB-N and TBA) and biochemical (water, ash, proteins, lipids and carbohydrates) quality of marinated mussels Mytilus galloprovincialis during vacuum-packaged storage during 15 days at 4°C.Obtained results of marinated mussels samples were compared with results of a control mussels samples. Total Volatile Basic Nitrogen (TVB-N) and Thiobarbituric acid (TBA) values were determined below the thresholds of acceptability limits values (25mg/ 100g and 3 mg MDA /kg respectively) during the storage period. TVB-N and TBA values were found as 14.3 ± 0.006 mg / 100g and 0.2 mg MDA/ Kg respectively for control mussel and 14.12 ± 0.02 mg / 100g and 0.3 mg MDA / Kg for marinated mussel. Total mesophilic flora for marinated mussels (3.21 log CFU / g) had significantly lower level compared to control group (4.14 log CFU/ g). Analysis evaluated a shelf life of 15 days for both batches with a significantly slower deterioration of the quality for the marinated batch.